Anatomy and Clinical Relevance of the Carotid Arteries

Overview

• Carotid Arteries: Major blood vessels in the neck supplying blood to the brain, neck, and face.
• Number: Two carotid arteries, one on each side of the body.
• Right Common Carotid Artery: Arises from the bifurcation of the brachiocephalic trunk.
• Left Common Carotid Artery: Branches directly from the arch of the aorta.
• Bifurcation: Both arteries split into external and internal branches at the carotid triangle.

Anatomy

• Carotid Sinus: Contains baroreceptors to regulate blood pressure.
• Carotid Body: Chemoreceptor important for oxygen level regulation.

External Carotid Artery

• Supplies blood to head and neck external to the cranium.
• Key Branches (ascending order):
  • Superior thyroid artery
  • Ascending pharyngeal artery
  • Lingual artery
  • Facial artery
  • Occipital artery
  • Posterior auricular artery
  • Maxillary artery
  • Superficial temporal artery

Internal Carotid Artery

• Supplies blood internally to the cranial cavity, brain, and eyes.
• Path: Through the carotid canal in the temporal bone.
• Forms the Circle of Willis and supplies the ophthalmic artery.

Clinical Relevance

Carotid Pulse

• Common site for assessing pulse rate, rhythm, and strength.
• Important to not palpate both simultaneously to prevent reduced blood flow.

Carotid Artery Hypersensitivity

• Caused by overreaction of carotid sinus baroreceptors.
• Triggered by external pressure, tight clothing, or head turning.
• Can cause syncope or presyncope; pacemaker for symptomatic cases.

Carotid Plaque (Atherosclerosis)

• Deposition of plaques reduces blood flow, risk of ischemic stroke.
• Assessment: Doppler study for vessel wall thickening.
• Treatment: Carotid endarterectomy or angioplasty and stenting.

Carotid Artery Aneurysm

• Balloon-like dilation, risk of rupture.
• Commonly affects the internal carotid artery.
• Clinical manifestations: Pulsatile neck mass, nerve compression symptoms, rupture.
• Diagnosis: Carotid angiography.

Carotid Artery Dissections

• Tear in artery wall creating abnormal blood flow channels.
• Common cause of stroke in young adults.
• Symptoms: Local pain, headache, Horner syndrome, ischemic stroke.
• Investigation: Digital subtraction angiography.

Amaurosis Fugax

• Temporary vision loss due to blocked blood vessel.
• Commonly due to cholesterol plaque from carotid artery.
• Symptoms: Sudden, painless, temporary vision loss.

Conclusion

• Carotid arteries are vital for blood supply to the brain, neck, and face.
• Clinical importance includes pulse assessment and conditions like hypersensitivity, plaques, aneurysms, dissections, and amaurosis fugax.